Nurses Compass
Drug Guide
Carphenazine Maleate
Classification
Therapeutic: Antipsychotic/Antiemetic
Pharmacological: Phenothiazine derivative with dopamine antagonism
FDA Approved Indications
- Psychotic disorders
- Nausea and vomiting, especially in cases resistant to other treatments
Mechanism of Action
Carphenazine Maleate exerts its effects primarily by blocking dopamine receptors in the brain, which can help diminish psychotic symptoms and control nausea and vomiting.
Dosage and Administration
Adult: Dosage varies depending on condition; typically, 10-25 mg 2-3 times daily, titrated as needed.
Pediatric: Not commonly used in children; consult specific guidelines.
Geriatric: Start at lower doses due to increased sensitivity; close monitoring required.
Renal Impairment: Adjust dosage based on clinical response; no specific guidelines available.
Hepatic Impairment: Use with caution; dose adjustments may be necessary due to reduced metabolism.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed in body tissues, including the brain.
Metabolism: Metabolized primarily in the liver.
Excretion: Excreted mainly in the urine.
Half Life: Approximately 8-12 hours, varies with individual metabolism.
Contraindications
- Hypersensitivity to phenothiazines or other components.
- Coma, CNS depression, or severe liver disease.
Precautions
- Use with caution in elderly due to risk of extrapyramidal symptoms and anticholinergic effects.
- Avoid in Parkinson’s disease due to dopamine blockade.
- Monitor for neuroleptic malignant syndrome, tardive dyskinesia.
Adverse Reactions - Common
- Sedation (Common)
- Dry mouth (Common)
- Hypotension (Common)
Adverse Reactions - Serious
- Extrapyramidal symptoms (Less common but serious)
- Neuroleptic malignant syndrome (Rare)
- Dose-related tardive dyskinesia (Rare)
Drug-Drug Interactions
- CNS depressants, other dopamine antagonists, anticholinergic drugs.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor mental status, neurological signs, blood pressure, and movement disorders.
Diagnoses:
- Risk of falls due to sedation or hypotension.
- Risk of movement disorders.
Implementation: Administer with food to decrease gastrointestinal upset; monitor for extrapyramidal symptoms; educate patient about potential side effects and safety precautions.
Evaluation: Assess effectiveness in controlling symptoms; observe for adverse reactions and adjust dosage accordingly.
Patient/Family Teaching
- Do not operate heavy machinery until you know how this medication affects you.
- Report any unusual movements, fever, or severe side effects immediately.
- Avoid alcohol and other CNS depressants.
- Take medication exactly as prescribed.
Special Considerations
Black Box Warnings:
- Potentially fatal neuroleptic malignant syndrome.
- Tardive dyskinesia may be irreversible.
Genetic Factors: No well-established genetic factors influencing response.
Lab Test Interference: Can cause false positives in certain urine drug screens.
Overdose Management
Signs/Symptoms: Excessive sedation, hypotension, extrapyramidal symptoms, seizures, coma.
Treatment: Supportive care, monitor vital signs, activated charcoal if ingestion was recent, manage symptoms symptomatically; no specific antidote.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable under recommended storage conditions.